The purpose of this invention is a mirror support, used in particular to adjust the position and orientation of mirrors reflecting a beam in a laser oscillating cavity.
Some lasers comprise a regenerating cavity through which light passes, being reflected in sequence on two mirrors at the ends. These mirrors must be oriented with very high precision to reflect the beam in the required direction. They may be provided with limited reflecting patterns that define the shape of the exit beam, which also makes it necessary to perfectly align them along the length of the path of the beam, by adjusting their side position, or even their angular position since their reflecting patterns are usually not circular.
Therefore, the positions of the two mirrors have to be adjusted with a great deal of care, and thus a search is made for an adjustable mirror support that offers sufficient adjustment precision and sensitivity, and that is stable and can be immobilized in order to be able to move the cavity without worrying about misadjusting the position of the mirrors. The invention satisfies these needs.
In its most general form, it relates to a mirror support characterized in that it comprises a frame, a lever suspended from the frame by springs, a mirror mounting at the end of an arm, the mirror being fixed to the mounting perpendicular to the arm, and two sets of adjustable stops and counter stops sliding through the frame and bearing on the lever, the stop and counter-stop assemblies sliding in the two directions perpendicular to each other and perpendicular to the lever respectively, the stops opposing movement of the springs, and the arm being articulated to the lever at an eccentric position of the lever and articulated to the frame. For the purposes of the invention, the counter stops are mechanical parts acting in opposition to the stops that are used to retain a part (in this case the lever) between them and the stops at a position defined by the position of the stops. The stops and the counter stops may consist of sets of opposing screws that may be on the same center line.
This device is sufficient to orient the mirrors, which is the most important constraint. If it is also required to adjust the alignment of the mirrors, then it is advantageous for the frame to comprise a fixed part, a first mobile part sliding on the fixed part in a first translation direction and a second mobile part sliding on the first mobile part in a second translation direction and from which the lever is suspended, springs connecting the first mobile part to the fixed part and to the second mobile part, and extending along the first and second directions of translation respectively, adjustable stops extending through the fixed part in the first translation direction as far as the first mobile part, and through the first mobile part in the second translation direction as far as the second mobile part, respectively, the stops opposing the force applied by the springs, and locking screws connecting the first mobile part and extending along the first translation direction and the second translation direction, respectively.
Finally, the angular position of the mirror as it rotates in its plane, can be adjusted if the mounting comprises a part fixed to the arm and a rotating tray on the part fixed to the arm, the mirror being fixed to the tray, and a means of adjusting the angular position of the tray.
Finally, it is advantageous if the stops are adjustment screws and the counter stops are pressure screws.
An excellent fineness of the orientation adjustment is obtained if each of the sets of stops and counter stops comprises a stop and counter stop close to the mounting and a stop and counter stop remote from the mounting, and if the arm is articulated to the frame close to the mirror and to the lever on the opposite side of the mirror and adjacent to the stop and to the counter stop remote from the mounting.